The Beyond Realm is a small Godverse-like dimension that resides outside the Omniverse. The reason for this is because the Beyond Realms' sole inhabitant is Beyonder. He is the totality of all existence within the realm. In this way, Beyonder is technically the embodiment of an entire Omniverse in himself. Such a level of existence would therefore grasp the outer limits (the little there are) of the Omniverse.